開發錯誤：java.lang.NoClassDefFoundError: org/json/JSONArray

問題原因：缺少了一個ezmorph.jar 包

需要以下jar包：

json-lib-2.4-jdk15.jar
commons-lang.jar
commons-beanutils.jar
commons-collections.jar
commons-logging.jar 
ezmorph.jar 

另一種解決方案是使用其他json,如fastjson.jar

附JSON使用：

1.JSONObject使用

public class JSONObjectUse {

    public static void main(String[] args) {
        //創建JSONObject對象
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username","wln");
        jsonObject.put("password","123");
        System.out.println("1：" + jsonObject);

        //增加屬性
        jsonObject.element("sex","男");
        System.out.println("2：" + jsonObject);

        //判斷輸出對象的類型
        boolean isArray = jsonObject.isArray();
        boolean isEmpty = jsonObject.isEmpty();
        boolean isNullObject = jsonObject.isNullObject();
        System.out.println("3：" + "是否是數組：" + isArray +" 是否是空：" + isEmpty + " 是否是空對象：" + isNullObject);

        //創建JSONArray
        JSONArray jsonArray = new JSONArray();
        jsonArray.add(0,"aa");
        jsonArray.add("BB");
        jsonArray.add(1,"AB");
        jsonArray.add("cc");

        //將JSONArray 添加到JSONObject
        jsonObject.element("student",jsonArray);
        System.out.println("4：" + jsonObject);
    }
}

結果：
1：{"username":"wln","password":"123"}
2：{"username":"wln","password":"123","sex":"男"}
3：是否是數組：false 是否是空：false 是否是空對象：false
4：{"username":"wln","password":"123","sex":"男","student":["aa","AB","BB","cc"]}

2.JSONArray的使用

public class JSONArrayUse {

    public static void main(String[] args) {
        //創建JSONArray對象
        JSONArray jsonArray = new JSONArray();
        jsonArray.add(0,"aa");
        jsonArray.add(1,"BB");
        jsonArray.element("cc");
        jsonArray.add("DD");
        System.out.println("1：" + jsonArray);
        //根據下標獲取數據
        System.out.println("2：" + jsonArray.get(0));

        //根據下標設置數據
        jsonArray.set(0,"AAA");
        System.out.println("3：" + jsonArray);

        //創建JSONObject
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username", "lwc");
        jsonObject.put("password", "123");
        //把JSONObject放入到JSONArray中
        jsonArray.add(jsonObject);
        System.out.println("4：" + jsonArray);

        //遍歷
        System.out.println("5：");
        for(int i=0;i<jsonArray.size();i++){
            System.out.print(jsonArray.get(i)+"\t");
        }
    }
}

結果：
1：["aa","BB","cc","DD"]
2：aa
3：["AAA","BB","cc","DD"]
4：["AAA","BB","cc","DD",{"username":"lwc","password":"123"}]
5：
AAA    BB    cc    DD    {"username":"lwc","password":"123"}

3.JavaBean與JSON字符串之間的轉換

public class JavaBeanUse {

    public static void main(String[] args) {
        //將JavaBean轉換爲JSONObject
        Student student = new Student("wln", "22");
        JSONObject jsonObject = JSONObject.fromObject(student);
        System.out.println("1：" + jsonObject);

        //將JSONString轉換爲JSONObject
        String jsonStr = "{\"name\":\"nana\",\"age\":\"33\"}";
        JSONObject jsonObject1 = JSONObject.fromObject(jsonStr);

        Student stu = (Student) JSONObject.toBean(jsonObject1,Student.class);
        System.out.println("2：" + stu);
        System.out.println("3：" + stu.getName() +" "+ stu.getAge());
    }
}

結果：
1：{"age":"22","name":"wln"}
2：com.springboot.devtools.jsonUse.entity.Student@61a485d2
3：nana 33

public class Student {

    private String name;
    private String age;

    public Student() {
    }

    public Student(String name, String age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

4.List與JSON字符串之間的轉換

public class ListUse {
    public static void main(String[] args) {
        //將List轉成JSONArray
        List list = new ArrayList();
        list.add(new Student("wln","22"));
        list.add(new Student("nana","33"));
        JSONArray jsonArray = JSONArray.fromObject(list);
        System.out.println("1：" + jsonArray);

        //將JSONString轉成List
        List list1 = new ArrayList();
        String strJSON = "[{\"name\":\"dada\",\"age\":\"44\"},{\"name\":\"xiaoxiao\",\"age\":\"55\"}]";
        JSONArray jsonArray1 = JSONArray.fromObject(strJSON);
        for(int i = 0;i < jsonArray1.size(); i++) {
            JSONObject jsonObject = jsonArray1.getJSONObject(i);
            Student stu = (Student) JSONObject.toBean(jsonObject,Student.class);
            list1.add(stu);
        }
        System.out.println("2：" + list1);
    }
}

結果：
1：[{"age":"22","name":"wln"},{"age":"33","name":"nana"}]
2：[com.springboot.devtools.jsonUse.entity.Student@7946e1f4, com.springboot.devtools.jsonUse.entity.Student@3c09711b]

5.Map與JSON字符串之間的轉換

public class MapUse {

    public static void main(String[] args) {
        //Map轉JSONString
        Map map = new HashMap();
        map.put("1", new Student("wln","22"));
        map.put("2", new Student("nana","33"));
        JSONObject jsonMap = JSONObject.fromObject(map);
        System.out.println("1：" + map);

        //JSONString轉Map
        String jsonStr = "{\"1\":{\"name\":\"dada\",\"age\":\"44\"},\"2\":{\"name\":\"xiaoxiao\",\"age\":\"55\"}}";
        Map map1 = (Map) JSONObject.fromObject(jsonStr);
        Set set = map1.keySet();
        Iterator ite = set.iterator();
        while (ite.hasNext()) {
            String key = (String) ite.next();
            JSONObject jsonObject = JSONObject.fromObject(map1.get(key));
            Student stu = (Student) JSONObject.toBean(jsonObject, Student.class);
            System.out.println("2：" + key + " " + stu);
        }
    }
}

結果：
1：{1=com.springboot.devtools.jsonUse.entity.Student@1b40d5f0, 2=com.springboot.devtools.jsonUse.entity.Student@ea4a92b}
2：1 com.springboot.devtools.jsonUse.entity.Student@3c09711b
2：2 com.springboot.devtools.jsonUse.entity.Student@5cc7c2a6

6.JSONArray與List之間的轉換

public class JSONArrayToList {
    public static void main(String[] args) {
        //List轉換爲JSONArray
        List<Student> list = new ArrayList<Student>();
        list.add(new Student("wln","22"));
        list.add(new Student("nana","33"));
        JSONArray jsonArray = JSONArray.fromObject(list);
        System.out.println("1：" + jsonArray);

        //JSONArray轉換爲List
        List<Student> list2 = JSONArray.toList(jsonArray, new Student(), new JsonConfig());
        Iterator<Student> ite = list2.iterator();
        while (ite.hasNext()) {
            Student stu = ite.next();
            System.out.println("2：" + stu);
        }
    }
}

結果：
1：[{"age":"22","name":"wln"},{"age":"33","name":"nana"}]
2：com.springboot.devtools.jsonUse.entity.Student@69d9c55
2：com.springboot.devtools.jsonUse.entity.Student@13a57a3b

7.JSONArray與數組之間的轉換

public class JSONArrayToArray {
    public static void main(String[] args) {
        //Java數組轉換JSONArray
        boolean[] boolArray = new boolean[] {true, false, true};
        JSONArray jsonArray = JSONArray.fromObject(boolArray);
        System.out.println("1："+ jsonArray.toString());

        //JSONArray轉換Java數組
        Object obj[] = jsonArray.toArray();
        for (Object o : obj) {
            System.out.print("2：" + o + " ");
        }
    }

}

結果：
1：[true,false,true]
2：true 2：false 2：true

8.XML與JSON之間的轉換

需要導入xom-1.1.jar

public class XMLToJSON {
    public static void main(String[] args) throws Exception {
        //XML轉換JSON
        String xml = "<root>" + "<name type='type'>wln</name>"
                + "<gender>woman</gender>" + "<birthday>" + "<year>1970</year>"
                + "<month>12</month>" + "<day>17</day>" + "</birthday>"
                + "</root>";
        XMLSerializer xmlSerializer = new XMLSerializer();
        JSON json = xmlSerializer.read(xml);
        System.out.println("1：" + json.toString(2));

        //JSON轉換XML
        String jsonStr = "{\"root\":{" + "\"name\":\"wln\","
                + "\"gender\":\"woman\"," + "\"birthday\":{"
                + "\"year\":\"1970\"," + "\"month\":\"12\"," + "\"day\":\"17\""
                + "}" + "}" + "}";
        JSONObject jsonObject = JSONObject.fromObject(jsonStr);
        String xmlStr = new XMLSerializer().write(jsonObject);
        System.out.println("2：" + xmlStr);
    }
}

結果：
1：{
  "name": "wln",
  "gender": "woman",
  "birthday":   {
    "year": "1970",
    "month": "12",
    "day": "17"
  }
}
2：<?xml version="1.0" encoding="UTF-8"?>
<o><root class="object"><birthday class="object"><day type="string">17</day><month type="string">12</month><year type="string">1970</year></birthday><gender type="string">woman</gender><name type="string">wln</name></root></o>

使用方法收集於：https://www.cnblogs.com/nananana/p/9263708.html